Although the present invention will be described hereinafter with reference to a diagnosis system management (DSM) for an engine control system, the present invention is not limited thereto.
A diagnosis system management (DSM) is used inter alia for controlling an operating procedure of an engine. The control takes place in accordance with predefined program sequences and on the basis of events which are sensed by sensors and communicated to the DSM. In addition, the DSM enables external analysis modules to record and analyze the program sequences during or after test phases and/or during routine operation of an engine.
Referring to FIG. 5, a schematic layout of a conventional DSM V for a control system H of an engine will be described. The operating procedure of an engine includes sequential and/or parallel execution of a plurality of function modules h1-h3, such as, for example, an actuator for spark plugs, a fuel tank ventilation system and an air-fuel mixture adapter. Those individual function modules h1-h3 are executed by a control system H. DSM V makes function modules h1-h3 available to control system H for execution, with DSM V selecting those function modules h1-h3 from a first set F of first function modules f1-f4 and a second set G of second function modules g1-g2.
Upon occurrence of events e1-e4, especially error messages, such as, for example, a defective spark plug, it is sensible for some of first function modules f1-f4 to be no longer made available to control system H for execution, so that, for example, gasoline is no longer injected into the corresponding cylinder having the defective spark plug. For that purpose, an event detecting device E is provided in DSM V. Event detecting device E detects events e1-e4 inter alia by sensors that monitor, for example, the spark plug. If an event e1-e4 is detected, an inhibitor module I is called. Inhibitor module I has a database which links event e1-e4 with first function modules f1-f4. In the example illustrated in FIG. 1, event e1 is associated with first function modules f1 and f4. Upon occurrence of event e1, execution of first function modules f1 and f4 is accordingly to be prevented. First function modules f1-f4 are assigned control statuses s1-s4 which are stored in registers in a memory device K. Inhibitor module I sets control statuses s1-s4 to designating blocking when their associated events e1-e4 have occurred. In the case described above, therefore, control statuses s1 and s4 are set to designating blocking. Management system V interrogates control statuses s1-s4. If those control statuses s1-s4 are set to designating blocking, management system V does not release the corresponding first function modules f1-f4 for execution and thus no longer makes them available to control system H for execution.
By reading memory device K it is possible to ascertain which function modules f1-f4 were blocked in the course of a test phase or a drive. This is advantageous for diagnosis of engine operation by the analysis module.
Second function modules g1-g2 are executed only if a corresponding event e1-e4 occurs or has occurred. Management system V is able inter alia to make a second function module g1-g2 available to control system H instead of a blocked function module f1-f4. Which of the second function modules g1-g2 will be made available is ascertained by management system V inter alia on the basis of internal algorithms of management system V. This may involve, for example, individual function modules f1-f4, g1-g2 being assigned priorities and, upon blocking of a prioritized function module, the next-in-priority function module being made available.
A disadvantage with this method is that it is not transparent to an external analysis module which of second function modules g1-g2 is capable of being made available by DSM V after an event e1-e4 has occurred. For an analysis, an analysis module therefore requires knowledge of the internal algorithms of management system V and must therefore be adapted to every new DSM.
A further disadvantage is that management system V has to examine for a second function module g1-g2 all the events e1-e4 associated with second function module g1-g2 before management system V is able to establish whether that second function module g1-g2 is or is not releasable for execution by control system H.